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• JavaFXFrameConverter consuming insane amounts of memory

  17 juillet 2023, par iexav

  The JavaFXFrameConverter (from the wrapper of the ffmpeg C library in java) convert() method is consuming an outrageous amount of memory. To elaborate a bit more, it does not happen usually. If I just make an instance of the class in my main method, grab a frame via FFMpegFrameGrabber and give it to the convert() method the memory usage is pretty much none. However, when I attempt to do pretty much the exact same in a class I made using an ExecutorService my memory usage jumps up to 8 gigabytes when convert is called. The converter and executor service are declared as member variables of my class. Namely :

  


      final JavaFXFrameConverter converter = new JavaFXFrameConverter();
    private  ExecutorService           videoExecutor;


  


  (the videoExecutor is instantiated in the constructor of the class :

  


  videoExecutor=Executors.newSingleThreadExecutor();


  


  Now, the method I am using for processing of the video frames is this :

  


      private void processVideo(){
        videoExecutor.submit(() -> {
            processingVideo.set(true);
            try{

                while(processingVideo.get() && (videoQueue.peek())!=null){

                    final Frame cloneFrame = videoQueue.poll();
                    final Image image = converter.convert(cloneFrame);
                    final long timeStampDeltaMicros = cloneFrame.timestamp - timer.elapsedMicros();
                    if (timeStampDeltaMicros > 0) {
                        final long delayMillis = timeStampDeltaMicros / 1000L;
                        try {
                            Thread.sleep(delayMillis);
                        } catch (InterruptedException e) {
                            Thread.currentThread().interrupt();
                        }
                    }

                    cloneFrame.close();
                    System.out.println("submitted image");
                videoListener.submitData(image);
                }
            }catch (NullPointerException e){
                NullPointerException ex = new NullPointerException("Error while processing video frames.");
            videoListener.notifyFailure(ex);
            }

            processingVideo.set(false);

        });
    }


  


  I sent the whole method for a bit more context but realistically speaking the only part that is of real significance is the converter.conver(cloneFrame) ; I used the intelliJ profiler and also the debugger and this is exactly where the problem occurs. When convert is called after doing some stuff it eventually ends up in this method :

  


          public <t extends="extends" buffer="buffer"> void getPixels(int x, int y, int w, int h, WritablePixelFormat<t> pixelformat, T buffer, int scanlineStride) {&#xA;            int fss = this.frame.imageStride;&#xA;            if (this.frame.imageChannels != 3) {&#xA;                throw new UnsupportedOperationException("We only support frames with imageChannels = 3 (BGR)");&#xA;            } else if (!(buffer instanceof ByteBuffer)) {&#xA;                throw new UnsupportedOperationException("We only support bytebuffers at the moment");&#xA;            } else {&#xA;                ByteBuffer bb = (ByteBuffer)buffer;&#xA;                ByteBuffer b = (ByteBuffer)this.frame.image[0];&#xA;&#xA;                for(int i = y; i &lt; y &#x2B; h; &#x2B;&#x2B;i) {&#xA;                    for(int j = x; j &lt; x &#x2B; w; &#x2B;&#x2B;j) {&#xA;                        int base = 3 * j;&#xA;                        bb.put(b.get(fss * i &#x2B; base));&#xA;                        bb.put(b.get(fss * i &#x2B; base &#x2B; 1));&#xA;                        bb.put(b.get(fss * i &#x2B; base &#x2B; 2));&#xA;                        bb.put((byte)-1);&#xA;                    }&#xA;                }&#xA;&#xA;            }&#xA;        }&#xA;</t></t>

  


  Now, everything up until this point is fine. The memory usage is at around 130mb but alas, when execution enters in these 2 for loops that's where the downright stupid memory usage occurs. Every single one of these bb.put calls is netting me around 3 more megabytes of memory usage. By the end of it you can probably guess what happens. Also all of these memory allocations do happen on the stack so I'm assuming that's why my memory usage stops at around 8-8.5 gigabytes otherwise the program would crash (that has also happened, out of memory exception thrown, but it doesn't usually happen, it kind of just lingers at those 8 gigabytes.) Frankly speaking I'm at a bit of a loss. I haven't seen virtually anyone anywhere mention this ever and I ran out of things to try to fix this so I am making this post.

  


  By the way another thing I tried is make the ExecutorService in the same class as the main method and when I submitted there I also didn't have these memory problems.

  


• How to use ffmpeg to create a video slideshow from a set of images ? [on hold]

  15 mars 2015, par Ali Irani

  I want to create a 15 second video from 5 images with a fade effect between them and add counter on center of video that changes every second. The final video also needs an audio track.

  Can I do this with ffmpeg ?

• FFMPEG video editing application. Need time and date stamp burned into video

  11 mai 2022, par Jacob

  I am developing an application for video editing. The main component of this application is to produce a single video file from several video files captured from a camcorder with the time and date stamp displayed on the final rendered video, much like the final product from a security camera. I have figured out, by using FFMPEG, how to burn the date and time into the video with a .SRT file as well as with DrawText like the following :

  


  ffmpeg -y -i video.mp4 -vf “drawtext=fontfile=roboto.ttf:fontsize=12:fontcolor=yellow:text='%{pts\:localtime\:1575526882\:%A, %d, %B %Y %I\\\:%M\\\:%S %p}'" -preset ultrafast -f mp4 output_new.mp4    


  


  I would rather use the DrawText method so the user does not have to wait longer while creating the .SRT files. I am new to FFMPEG and I find their documentation very confusing. I guess I am hoping there is someone out there who has experience with it.

  


  Everything seems to work when I pass in the date created meta data from the video file and drawtext just does its thing. The problem is my application allows for editing of the video. I do this, for lack of better solution, by allowing the user to select beginning and ending frames they do not want, from the UI and then the code simply deletes the frames from the directory where they were split and saved. I then use FFMPEG to iterate through the directory and combine the remaining frames to make a video file.

  


  This approach starts the time and date from the date created metadata ; however, cutting the frames out of the video will make the DT stamp inaccurate, due to the missing frames.

  


  Is there any way to tell FFMPEG to burn in the date and time from date/time retrieved from each individual frame ? I appreciate any advice that you may have.